1. Field of the Invention
The present invention relates to an encryption apparatus for generating encryption data, a program for use therewith, and a method for use therewith.
2. Description of the Related Art
For example, an authentication system performs authentication by using encryption data generated by an encryption apparatus. Based on, for example, correspondence table data for indicating a correspondence relationship between input data and plaintext data, such an encryption apparatus specifies plaintext data corresponding to the input data, and encrypts the specified plaintext data in order to generate encryption data. A conventional encryption apparatus encrypts the above-described specified plaintext data by a predetermined single encryption method.
However, in the above-described conventional encryption apparatus, since only a single encryption method is adopted, if the above-described correspondence table data and encryption method are illegally obtained, the encryption data can be illegally generated. For this reason, in an authentication system using such an encryption apparatus, there have been demands for preventing encryption data from being illegally generated and for increasing authentication reliability.
The present invention has been made in view of such a situation. An object of the present invention is to provide an encryption apparatus capable of effectively preventing encryption data from being illegally generated, a program for use therewith, and a data processing apparatus for use therewith.
To achieve the above-mentioned object, in a first aspect, the present invention provides an encryption apparatus for generating encryption data on the basis of specified identification data, the encryption apparatus including: first selection means for selecting an encryption method from among a plurality of different encryption methods on the basis of the identification data; second selection means for selecting plaintext data to be encrypted from among a plurality of different pieces of the plaintext on the basis of the identification data; and encryption means for obtaining encryption data such that the plaintext data selected by the second selection means is encrypted by the encryption method selected by the first selection means.
In the encryption apparatus in accordance with the first aspect of the present invention, the first selection means may select an encryption method from among a plurality of different encryption methods on the basis of the identification data. The second selection means may select plaintext data to be encrypted from among a plurality of different pieces of the plaintext on the basis of the identification data. The encryption means may obtain encryption data such that the plaintext data selected by the second selection means is encrypted by the encryption method selected by the first selection means.
In a second aspect, the present invention provides a program executed by a data processing apparatus for generating encryption data on the basis of specified identification data, the program enabling the data processing apparatus to execute processing including: a first procedure for selecting an encryption method from among a plurality of different encryption methods on the basis of the identification data; a second procedure for selecting plaintext data to be encrypted from among a plurality of different pieces of plaintext data on the basis of the identification data; and a third procedure for obtaining encryption data such that the plaintext data selected in the second procedure is encrypted by the encryption method selected in the first procedure.
In the program in accordance with the second aspect of the present invention, in the first procedure of the program, the data processing apparatus may select an encryption method from among a plurality of different encryption methods on the basis of the identification data. In the second procedure, the data processing apparatus may select plaintext data to be encrypted from among a plurality of different plaintext data on the basis of the identification data. In the third procedure, the data processing apparatus may obtain encryption data such that the plaintext data selected in the second procedure is encrypted by the encryption method selected in the first procedure.
In a third aspect, the present invention provides a data processing method for use with a data processing apparatus for generating encryption data on the basis of specified identification data, the data processing method including: a first step of selecting an encryption method from among a plurality of different encryption methods on the basis of the identification data; a second step of selecting plaintext data to be encrypted from among a plurality of different pieces of plaintext data on the basis of the identification data; and a third step of obtaining encryption data such that the plaintext data selected in the second step is encrypted by the encryption method selected in the first step.
In the data processing method in accordance with the third aspect of the present invention, in the first step, the data processing apparatus selects an encryption method from among a plurality of different encryption methods on the basis of the identification data. In the second step, the data processing apparatus selects plaintext data to be encrypted from among a plurality of different pieces of plaintext data on the basis of the identification data. In the third step, the data processing apparatus obtains encryption data such that the plaintext data selected in the second step is encrypted by the encryption method selected in the first step.
According to the present invention, it is possible to provide an encryption apparatus capable of effectively preventing encryption data from being illegally generated, a program for use therewith, and a data processing apparatus for use therewith.